The present invention relates generally to containers for retaining, protecting and displaying articles and methods for making such containers. In particular, the present invention relates to a container having an open top formed from corrugated paperboard material which is useful in shipping and displaying perishable produce.
Flat sheets of corrugated paperboard, typically referred to as blanks, have been used for many years as the starting material to form produce containers. Corrugated paperboard generally refers to a multi-layer sheet material comprised of two sheets of liner bonded to a central corrugated layer. Given a basic size requirement specified by the customer, industry standards and the preference for low cost, paperboard container manufacturers strive to provide structural stacking strength with a minimal amount of corrugated paperboard. A typical well-known container is a single piece tray design having a bottom wall, two side walls and two end walls, each of the side and end walls being hinged to the bottom wall. Typically, a single piece of corrugated paperboard will be cut and scored to form a flat blank that will then be folded into this container.
Typical containers for the support and transport of food produce articles are corrugated containers having fixed configurations. These containers can be unstable when stacked and are conducive to toppling. Many containers are not durable and flexible enough to protect and prevent damage to the produce. Furthermore, the side and bottom walls of produce containers are susceptible to buckling and twisting, leading to damage to the produce.
A packed container of produce will generally hold a weight suitable for handling by an individual. Such containers will generally be rectangular and have a variable height dimension. Further, these containers will normally be stacked for transport and storage. The cost of labor, i.e., the time required to handle the produce and assemble the shipping containers, can be significant factors in the overall cost of the produce. Many current produce containers can only be assembled by hand, a method that is costly and time consuming. Assembling paperboard containers for setup by a machine, where cooperating adjoining paperboard sections are adhesively bonded to form the produce container, can reduce cost and time.
It is important in the production, distribution and sale of perishable and non-perishable articles, such as produce, that the articles are safely and conveniently stored for transport and are safely and securely shipped for sale. Safe and secure storage and shipping is particularly a problem if heavy items must be placed in containers that are stacked on each other. Stackable produce containers often acquire, for example, bulging side or end walls, deformed bottom walls, or smashed corners that damage the produce due to, for example, the weight or movement of the produce during shipment. Further, if the environment in which the paperboard container is shipped or stored is refrigerated, the moisture present is likely to be absorbed by and weaken the container.
Once the produce reaches a retail destination, the produce container is normally placed directly on display for consumer sale. This allows retailers to preserve time and money by not having to transfer produce into an alternative selling container. If a produce container arrives to a retailer in a crushed or damaged state, however, the retailer usually cannot, for aesthetic purposes, exhibit the produce container. Furthermore, produce containers generally contain at least one or more visible panels that have not been painted or coated. Retailers that sell produce directly in the container that emanates from the grower usually do not, for aesthetic reasons, desire consumers to see unpainted or uncoated surfaces.
Vertically-oriented corrugation within a produce container is typically stronger and more secure than horizontally-oriented corrugation. Without structural rigidity, containers at or near the bottom of a stack of produce containers could buckle under the weight of the containers stacked above them. Generally, the end walls of a produce container contain vertically-oriented corrugation. Thus, it is preferable for the end walls to contain as few openings as possible. Optimal cooling efficiency, which enhances produce quality and shelf life, is also desirable. Cooling may be achieved by including openings in the walls to allow cool air to flow from one side of the container to the other.
Accordingly, it is desirable to provide a container for transporting produce that is both durable and secure to prevent corrugation failure and produce damage, and which permits painting or coating on all visible surfaces, yet allows sufficient air flow to achieve optimal cooling efficiency.
The invention generally relates to a stackable produce container formed from a one-piece flat blank, typically of corrugated paper stock. The container is reinforced to permit use with heavy produce, such as melons, while resisting bulging of the side panels or bottom resulting from the load and/or the effects of high humidity.
In one aspect, the container of the invention is a rectangular, unitary structure having at least two compartments defined by side panels and a bottom panel, each compartment being separated from an adjacent compartment by a transverse rib and two vertical ribs. The four corners of the container are reinforced, preferably by at least one panel disposed at an angle to each of the adjacent side panels.
In one embodiment, the container of the invention has two compartments separated by one transverse rib and two vertical ribs which engage the ends of said transverse rib.
In a preferred embodiment, the top of the transverse rib is curved upwardly to increase the strength of the rib. In another preferred embodiment, the bottom of the transverse rib is curved upwardly to prestress the adjacent bottom panels.
In some embodiments, the vertical ribs engage the outside of the associated transverse rib. In other embodiments, the vertical ribs engage the inside of the associated transverse rib.
In some embodiments, the transverse rib has a height lower than the side walls of the container. In other embodiments, the transverse rib has the same height as the side walls of the container. In that case, the vertical ribs are modified but still support the transverse rib.